Medici secretary and diplomat Orazio della Rena was the son of the Fulvio di Giuliano della Rena from Colle Val d'Elsa e di Aspasia di Aonio Paleario. He was born in Prato where his father worked as a doctor, but spent much of his childhood at the family villa at Galognano near Colle. After studying law at the University of Pisa, Orazio began a career at the Medici court under the protection of secretary Piero Usimbardi, gaining appointments as embassy secretary in Ferrara and in Spain. While he was secretary of the Medici embassy in Ferrara Della Rena wrote an in depth report entitled "Relazione dello Stato di Ferrara" which was published in 1896. As the secretary of the Medici embassy in Spain Della Rena wrote several similar reports of the state of the nation including the manuscript "Monarchia spagnuola" (Florence, Bibl.Naz.) and handled several delicate diplomatic tasks including the delivery of gifts to Beatrix Meneses, the bride of don Pietro de' Medici, and the negotiations concerning don Pietro's illegitimate children. After he returned to Italy, Della Rena was sent to work at the Medici embassy in Rome for a period and was later given several important administrative appointments at the Medici court. Orazio della Rena is also known as a scholar and as the author of several essays including "Prosapia del Salvatore del genere umano", 1620. Other works have been attributed to Della Rena including a life of Grand Duke Ferdinando I entitled "Vita di Ferdinando di Toscana" and the "Serie breve de' vescovi". Late in life Orazio retired to the family villa at Galognano where he died. Della Rena was buried in the church of San Francesco al Monte. He and his wife Margherita Quaratesi had two sons Cosimo (born 8 January 1615) and Ferdinando (born 27 May 1616).